Two-dimensional anode catalyst, preparation method thereof and application of two-dimensional anode catalyst in water electrolysis hydrogen production

Abstract

The invention provides a preparation method of a two-dimensional anode catalyst for hydrogen production by water electrolysis, which comprises the following steps: firstly, pressing and calcining a precursor at high pressure to form a layered precursor IrxRuyAlzC, then etching an Al atomic layer in the layered IrxRuyAlzC by an etching intercalation solution to form a vacancy, then inserting Li < + > with smaller atomic radius into the interlayer, and further performing ultrasonic stripping and calcining to obtain a two-dimensional IrxRuyO nanosheet. The catalyst disclosed by the invention is a flaky iridium-containing binary or ternary alloy oxide, can be used as an anode catalyst for hydrogen production by electrolysis of water, and has high specific surface area and relatively high OER catalytic activity.

Description

Technical Field

[0001] The present invention belongs to the field of water electrolysis hydrogen production catalysts, and in particular relates to a two-dimensional anode catalyst and a preparation method thereof and application thereof in water electrolysis hydrogen production. Background Art

[0002] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention, and should not necessarily be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art.

[0003] At present, PEM water electrolysis hydrogen production technology has not yet been realized on a large scale commercial application. Compared with other hydrogen production technologies, there is still a gap in cost, efficiency and reliability. Only by further reducing the cost of PEM hydrogen production and improving hydrogen production efficiency and durability can it gain a larger share in the market, which is the key to realizing the large-scale application of PEM water electrolysis hydrogen production.

[0004] Generally, two-dimensional nanomaterials have good electrochemically active surface area and excellent catalytic activity, which can effectively reduce the dosage of precious metals and improve catalytic efficiency. However, the strategies for preparing two-dimensional nanomaterials have the defects of complex preparation process, low yield and difficulty in industrialization. Therefore, it is of research significance to develop a solution to overcome the above shortcomings.

[0005] So far, various strategies have been developed to manufacture two-dimensional metal oxides, including vapor deposition and liquid phase methods. Vapor deposition methods include physical and chemical vapor deposition methods. This method is conducive to the production of high-quality, large-area and thickness-controlled oxide nanosheets. However, this method usually involves a complex and harsh synthesis process. The yield is low and cannot be used for large-scale production. In contrast, the liquid phase method (including liquid phase exfoliation and wet chemical method) is low in cost and simple to operate, and is considered to be one of the effective methods for producing two-dimensional oxides. However, the inventors have found that the liquid phase exfoliation method is only suitable for exfoliating oxides with a layered structure, while most oxides have a non-layered structure, and their atoms or molecules have the same strength in all dimensions. Therefore, the preparation of iridium-containing two-dimensional multi-metal oxide catalysts using liquid phase exfoliation methods remains a huge challenge. Summary of the invention

[0006] In order to solve the above problems, the present invention provides a two-dimensional anode catalyst, a preparation method thereof and its application in hydrogen production by electrolysis of water. The catalyst is a flaky iridium-containing binary or ternary alloy oxide, which can be used as an anode catalyst for hydrogen production by electrolysis of water, and has a high specific surface area and high OER catalytic activity.

[0007] In order to achieve the above object, the present invention adopts the following technical solution:

[0008] The first aspect of the present invention provides a method for preparing a two-dimensional anode catalyst, comprising:

[0009] The iridium source is mixed with the active metal A source, the main group metal B source and the carbon source and pressed into a sheet, and then pyrolyzed and calcined under oxygen-free conditions to obtain a precursor Ir with a layered structure. x A y B z C; wherein the active metal A is ruthenium, iron, cobalt, nickel, manganese or copper, and the main group metal B is aluminum or silicon;

[0010] The precursor Ir is x A y B z The main group metal B in C is removed, and layered metal carbide Ir is obtained through intercalation and stripping. x A y C;

[0011] In an oxygen-containing atmosphere, the layered metal carbide Ir x A y C was oxidized and calcined to oxidize the carbide into oxide to obtain a two-dimensional layered metal alloy oxide catalyst Ir x A y O, that is, a two-dimensional anode catalyst.

[0012] The present invention first prepares a precursor Ir having a layered structure x A y B z C, and then prepare layered metal carbide Ir x A y C, and then oxidized to form a two-dimensional layered metal alloy oxide catalyst Ir x A y O, this process ensures that the microstructure of the prepared material is two-dimensional layered by first forming layered carbides, and finally through oxidation calcination, a two-dimensional multi-metal oxide catalyst containing iridium can be obtained, avoiding the problem that it is difficult to form a layered structure when directly preparing oxides.

[0013] The iridium source described in the present invention refers to a single substance, compound (such as inorganic salts, organic salts, hydroxides, oxides, carbides, nitrides, etc.) or mixture containing a metal element and the metal element is only iridium. In some embodiments, the iridium source is selected from one or more of chloroiridic acid, iridium acetylacetonate, iridium chloride, potassium chloroiridate, sodium chloroiridate, and iridium acetate.

[0014] The active metal A source described in the present invention refers to a single substance, compound (such as inorganic salts, organic salts, hydroxides, oxides, carbides, nitrides, etc.) or mixture containing a metal element and the metal element is only active metal A. In some embodiments, the active metal A source is a metal powder containing active metal A or one or more of nitrates, halides, sulfates, acetates, etc. of active metal A.

[0015] The main group metal B source described in the present invention refers to a single substance, compound (such as inorganic salts, organic salts, hydroxides, oxides, carbides, nitrides, etc.) or mixture containing a metal element and the metal element is only the main group metal B. In some embodiments, the main group metal B source is a metal powder containing the main group metal B or at least one of the carbides and nitrides of the main group metal B.

[0016] The carbon source described in the present invention refers to a carbon single material or a substance that can form a carbon single material after pyrolysis, and can be a commercially available or homemade carbon material such as carbon black, a high specific surface area carbon material, a high graphitization degree carbon material, porous carbon, mesoporous carbon, carbon nanotubes, nitrogen-doped carbon, boron-doped carbon, sulfur-doped carbon and / or phosphorus-doped carbon, carbon nanofibers, graphene and aerogel, etc.

[0017] The precursor Ir of the present invention x A y B z The x, y, and z in C refer to the stoichiometric numbers of the corresponding elements in the substance, which can be determined by the amount of each element added during the preparation process.

[0018] In some embodiments, the atomic ratio of iridium atoms in the iridium source to active metal A atoms in the active metal A source is 1:0.1-5.

[0019] In some embodiments, the atomic ratio of iridium atoms in the iridium source to main group metal B atoms in the main group metal B source is 3:1-2.

[0020] In some embodiments, the mass ratio of the iridium source to the carbon source is 1:0.5-5.

[0021] In the present invention, the iridium source, the active metal A source, the main group metal B source and the carbon powder can be mixed in any mixing manner, such as ball milling, grinding, and dry mixing. In some embodiments, the iridium source, the active metal A source, the main group metal B source and the carbon powder are mixed in a ball milling manner. Specifically, the ball milling process has a rotation speed of 100-1000 r / min and a ball milling time of 1-10 h.

[0022] In some embodiments, during the tableting, the pressure used is in the range of 0.1-30 MPa, the pressing time is 1-30 min, and the number of pressing times is 1-10 times.

[0023] The oxygen-free condition of the present invention may be an inert atmosphere condition or a vacuum condition. The inert atmosphere condition refers to a gas atmosphere formed by an inert gas such as nitrogen or helium, neon, argon, etc.

[0024] In some embodiments, the temperature of the pyrolysis calcination is 900-1500°C, and the time of the pyrolysis calcination is 2-10 hours. The present invention can better achieve the layered arrangement of metal iridium atoms, metal atoms A, B and carbon atoms at the atomic scale by controlling the atmosphere and temperature of the pyrolysis calcination process, thereby obtaining a precursor Ir having a layered structure. x A y B z C.

[0025] The present invention uses the precursor Ir x A y B z In the removal of the main group metal B in C, the etching method generally uses HF solution to etch, and the HF solution can selectively etch away the precursor Ir x A y B z C, thereby removing the main group metal B. However, directly adding HF solution is prone to safety issues, so fluoride salt and hydrochloric acid can be used together to form HF to remove the precursor Ir x A y B z In addition, when the fluoride salt is lithium fluoride, it can provide lithium ions, which, after etching away the main group metal B, will have a smaller atomic radius. + It can be inserted between layers, that is, the combination of lithium fluoride and hydrochloric acid can not only etch the main group metal B, but also play the role of intercalation, thereby facilitating subsequent stripping.

[0026] In some embodiments, the etching method uses a mixture of lithium fluoride and hydrochloric acid solution as an etching solution. The operation process is to add the precursor Ir x A y B z C etches away metal atoms B under constant temperature water bath conditions and intercalates lithium atoms into the precursor Ir x A y B z C's layered structure, and an intercalated product is obtained.

[0027] Specifically, the concentration of the hydrochloric acid solution is 1-6 mol / L, and the mass ratio of lithium fluoride to the hydrochloric acid solution is 1:10-50.

[0028] Specifically, the precursor Ir x A y Bz The mass ratio of C to etching solution is 1:10-100.

[0029] Specifically, the precursor Ir is etched x A y B z The temperature for removing the main group metal B in C is 35-60°C, and the etching time is 10-24h.

[0030] In some embodiments, the intercalation product is washed after intercalation and then subjected to ultrasonic stripping. The specific process is: the intercalation product is washed to a pH of 5.5-7, dispersed in a solvent, subjected to ultrasonic stripping, solid-liquid separation, the upper liquid is collected, and dried to obtain a layered metal carbide Ir x A y C.

[0031] Specifically, during the ultrasonic stripping process, the solvent and the precursor Ir x A y B z The mass ratio of C is 10-100:1;

[0032] Specifically, the ultrasonic stripping time is 0.5-3h.

[0033] Specifically, the solid-liquid separation method is centrifugation, and the low-speed centrifugation speed is 1000-3000r / min.

[0034] The oxygen-containing atmosphere conditions described in the present invention refer to an atmosphere containing oxygen, which can be an air atmosphere, an oxygen atmosphere, or a mixed gas atmosphere of air and oxygen.

[0035] In some embodiments, during the oxidative calcination, the calcination temperature is 300-650° C., and the calcination time is 1-3 h.

[0036] More specifically, it includes:

[0037] (1) Precursor Ir x A y B z C preparation: The iridium source is ball-milled with the active metal A, the main group metal B and the carbon source, and then the ball-milled precursor mixture is repeatedly pressed into thin sheets under high pressure conditions and then calcined at high temperature in an inert atmosphere or vacuum environment to obtain a precursor Ir with a layered structure. x A y B z C;

[0038] (2) Etching intercalation: Slowly add lithium fluoride / lithium chloride into the hydrochloric acid solution under room temperature water bath conditions and stir until the lithium salt is completely dissolved. Then slowly add the precursor Ir x Ay B z C and heated in a constant temperature water bath to x A y B z C is intercalated to etch away the precursor Ir x A y B z The metal atoms B in C are arranged in layers and the lithium atoms with smaller atomic radius are intercalated into the precursor Ir x A y B z The layered structure of C facilitates subsequent ultrasonic peeling;

[0039] (3) Stripping: The above product is centrifuged and washed with water for multiple times until the pH is close to 5.5-7, and then an appropriate amount of deionized water is added for ultrasonic stripping. Finally, the block products and impurities that cannot be stripped are removed by low-speed centrifugation. The upper liquid is retained and dried for later use, and the stripped layered metal carbide Ir is obtained. x A y C;

[0040] (4) Finally, oxidation is performed: the dried layered metal carbide Ir x A y C can be calcined at high temperature in air / oxygen atmosphere to obtain a two-dimensional layered metal alloy oxide catalyst Ir x A y O.

[0041] The second aspect of the present invention provides a two-dimensional water electrolysis hydrogen production anode catalyst prepared by the above method.

[0042] The third aspect of the present invention provides the use of the above-mentioned two-dimensional water electrolysis hydrogen production anode catalyst in water electrolysis hydrogen production.

[0043] Beneficial Effects of the Invention

[0044] (1) The two-dimensional nanomaterials prepared by the present invention can significantly reduce the loading of precious metals and effectively reduce the cost of membrane electrodes.

[0045] (2) The two-dimensional alloy nanosheet structure prepared by the present invention has a nanometer-level thickness and a high ECSA, and its reactive phase interface is almost completely exposed, which can greatly increase the mass-charge transfer rate and accelerate the reaction.

[0046] (3) The two-dimensional nanostructure prepared by the present invention can effectively reduce the reaction energy barrier and improve the catalyst reaction activity due to its unique two-dimensional nanometer size effect and alloyed electronic structure.

[0047] (4) The preparation method of the present invention is simple, practical and easy to promote. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention, and the exemplary embodiments of the present invention and their description are used to explain the present invention and do not constitute improper limitations on the present invention.

[0049] Figure 1 This is a flow chart of preparing two-dimensional IrxRuyO nanosheets by intercalation etching method in Example 1 of the present invention;

[0050] Figure 2 The precursor Ir in Example 1 of the present invention x Ru y Al z C SEM photos of tablets after heat treatment;

[0051] Figure 3 The Ir obtained after etching the intercalation layer in Example 1 of the present invention x Ru y SEM image of C;

[0052] Figure 4 is Ir in Example 1 of the present invention x Ru y SEM (A) and TEM (B) images of O;

[0053] Figure 5 This is a diagram of the specific surface area of ​​the catalyst in Example 1 of the present invention;

[0054] Figure 6 This is a comparison chart of the half-cell performance of the catalyst in Example 1 of the present invention and the catalyst in the commercial comparative example;

[0055] Figure 7 This is a comparison chart of membrane electrode performance between the catalyst in Example 1 of the present invention and the catalyst in a commercial comparative example;

[0056] Figure 8 This is a durability performance diagram of the catalyst membrane electrode in Example 1 of the present invention. DETAILED DESCRIPTION

[0057] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0058] Explanation of terms

[0059] PEM: proton exchange membrane;

[0060] MEA: membrane electrode;

[0061] OER: oxygen evolution reaction (occurs at the anode of water electrolysis).

[0062] The present invention will be further described in detail below in conjunction with specific embodiments. It should be noted that the specific embodiments are intended to explain the present invention rather than to limit it.

[0063] Example 1

[0064] A method for preparing a two-dimensional anode catalyst, such as Figure 1 As shown, the precursor is first pressed and calcined under high pressure to form a layered precursor Ir x Ru y Al z C, and then the layered Ir x Ru y Al z The Al atomic layer in C forms a vacancy, followed by the Li with a smaller atomic radius. + Insertion between layers, followed by ultrasonic exfoliation and calcination, can produce two-dimensional Ir x Ru y O nanosheets, the specific steps are as follows:

[0065] First, 1g of chloroiridic acid was ball-milled with 2g of ruthenium chloride, 3g of aluminum powder and 4g of carbon black (rotation speed 500r / min) for 5h. Then, the ball-milled precursor mixture was pressed at 20MPa pressure for 1min, and the pressing was repeated 5 times to form a thin sheet. After that, the thin sheet was calcined at 1300℃ for 3h in an argon atmosphere to obtain a precursor Ir with a layered structure. x Ru y Al z C Figure 2 shown.

[0066] Then prepare the intercalation etching solution, slowly add 1g lithium fluoride into 50g 6mol / L hydrochloric acid solution under room temperature water bath conditions, and stir until the lithium salt is completely dissolved, then slowly add 1g precursor Ir x Ru y Al z C and heated in a constant temperature water bath at 40 °C for 10 h to x Ru y Al z C was intercalated and etched, and then the above product was centrifuged and washed with water for several times until the pH was 7 to obtain the etched Ir x Ru y C Figure 3 shown.

[0067] Stripping: Add 50 mL of deionized water to the above product and perform ultrasonic stripping for 2 h. Finally, centrifuge at a low speed of 2000 r / min to remove the blocky products and impurities that cannot be stripped. The upper liquid is retained and freeze-dried for later use to obtain the stripped layered metal carbide Ir x Ruy C nanosheets, and finally the dried layered metal carbide Ir x Ru y C nanosheets were heated to 500°C at a rate of 5°C / min in air atmosphere and calcined at high temperature for 3 h to obtain a two-dimensional layered metal alloy oxide catalyst Ir x Ru y O, that is, a two-dimensional anode catalyst; the SEM / TEM photos of the obtained catalyst are shown in Figure 4 shown.

[0068] The specific surface area of ​​the catalyst obtained is Figure 5 As shown, the specific surface area is as high as 284.7m 2 / g, which is higher than other competing catalysts, showing the characteristics of high specific surface area of ​​two-dimensional sheet nanomaterials, which can greatly increase the reaction active area and expose more reaction active sites.

[0069] Table 1 Comparison of specific surface areas of catalysts

[0070] name structure Specific surface area <![CDATA[Ir x Ru y O-Salt Template]]> <![CDATA[Ir x Ru y O]]> 284.7 Comparative Example 1 Imported catalyst 84.30 Comparative Example 2 Imported catalyst 35.76 Comparative Example 3 Domestic catalyst 33.70

[0071] from Figure 6 It can be seen that the half-cell performance of the two-dimensional IrxRuyO nanosheets prepared by intercalation etching is much better than that of other competing catalysts. 2 Single cell performance at extremely low Ir loading ( Figure 7 )、Durability( Figure 8 ) are superior to the comparative catalysts, showing excellent electrochemical activity, and the durability has no obvious attenuation after 1000h. It is expected to further reduce the Ir loading of PEM water electrolysis hydrogen production membrane electrode.

[0072] Example 2

[0073] A method for preparing a two-dimensional anode catalyst, the specific steps are as follows:

[0074] First, 1g of chloroiridic acid was ball-milled with 2g of ruthenium chloride, 3g of aluminum powder and 4g of carbon black (rotation speed 800r / min) for 3h. Then, the ball-milled precursor mixture was pressed at a pressure of 10MPa for 10min, and the pressing was repeated 6 times to form a thin sheet. After that, the thin sheet was calcined at 1200℃ for 8h in an argon atmosphere to obtain a precursor Ir with a layered structure. x Ru y Al z C.

[0075] Then prepare the intercalation etching solution, slowly add 1g lithium fluoride into 40g 6mol / L hydrochloric acid solution in a room temperature water bath, and stir until the lithium salt is completely dissolved, then slowly add 1g precursor Ir xRu y Al z C and heated in a constant temperature water bath at 60 °C for 10 h to x Ru y Al z C was intercalated and etched, and then the above product was centrifuged and washed with water for several times until the pH was 7 to obtain the etched Ir x Ru y C.

[0076] Stripping: Add 50 mL of deionized water to the above product and perform ultrasonic stripping for 0.5 h. Finally, centrifuge at a low speed of 1000 r / min to remove the blocky products and impurities that cannot be stripped. The upper liquid is retained and freeze-dried for later use. The stripped layered metal carbide Ir x Ru y C nanosheets, and finally the dried layered metal carbide Ir x Ru y The C nanosheets were obtained by heating the temperature to 600°C at a heating rate of 5°C / min in an air atmosphere and calcining at high temperature for 2h.

[0077] Example 3

[0078] A method for preparing a two-dimensional anode catalyst, the specific steps are as follows:

[0079] First, 1g of chloroiridic acid was ball-milled with 2g of ruthenium chloride, 3g of aluminum powder and 4g of carbon black (rotation speed 300r / min) for 8h. Then, the ball-milled precursor mixture was pressed at 30MPa pressure for 1min, and the pressing was repeated 3 times to form a thin sheet. After that, the thin sheet was calcined at 900℃ for 10h in an argon atmosphere to obtain a precursor Ir with a layered structure. x Ru y Al z C.

[0080] Then prepare the intercalation etching solution, slowly add 1g lithium fluoride into 50g 4mol / L hydrochloric acid solution in a room temperature water bath, and stir until the lithium salt is completely dissolved, then slowly add 1g precursor Ir x Ru y Al z C and heated in a constant temperature water bath at 35 °C for 24 h to x Ru y Al z C was intercalated and etched, and then the above product was centrifuged and washed with water for several times until the pH was 6.5 to obtain the etched Ir x Ru y C.

[0081] Stripping: Add 50 mL of deionized water to the above product and perform ultrasonic stripping for 1 h. Finally, centrifuge at a low speed of 3000 r / min to remove the blocky products and impurities that cannot be stripped. The upper liquid is retained and freeze-dried for later use. The stripped layered metal carbide Ir x Ru y C nanosheets, and finally the dried layered metal carbide Ir x Ru y The C nanosheets were obtained by heating the temperature to 300°C at a heating rate of 5°C / min in an air atmosphere and calcining at high temperature for 3 hours.

[0082] Example 4

[0083] A method for preparing a two-dimensional anode catalyst, the specific steps are as follows:

[0084] First, 1g of chloroiridic acid was ball-milled with 2g of ruthenium chloride, 3g of silicon powder and 4g of carbon black (rotation speed 500r / min) for 5h. Then, the ball-milled precursor mixture was pressed at 20MPa pressure for 1min, and the pressing was repeated 5 times to form a thin sheet. After that, the thin sheet was calcined at 1300℃ for 3h in an argon atmosphere to obtain a layered precursor Ir x Ru y Al z C.

[0085] Then prepare the intercalation etching solution, slowly add 1g lithium fluoride into 50g 6mol / L hydrochloric acid solution under room temperature water bath conditions, and stir until the lithium salt is completely dissolved, then slowly add 1g precursor Ir x Ru y Al z C and heated in a constant temperature water bath at 40 °C for 10 h to x Ru y Al z C was intercalated and etched, and then the above product was centrifuged and washed with water for several times until the pH was 7 to obtain the etched Ir x Ru y C.

[0086] Stripping: Add 50 mL of deionized water to the above product and perform ultrasonic stripping for 2 h. Finally, centrifuge at a low speed of 2000 r / min to remove the blocky products and impurities that cannot be stripped. The upper liquid is retained and freeze-dried for later use to obtain the stripped layered metal carbide Ir x Ru y C nanosheets, and finally the dried layered metal carbide Ir x Ru y The C nanosheets were obtained by heating the temperature to 500°C at a heating rate of 5°C / min in an air atmosphere and calcining at high temperature for 3 hours.

[0087] Example 5

[0088] A method for preparing a two-dimensional anode catalyst, the specific steps are as follows:

[0089] First, 1g of chloroiridic acid was ball-milled with 2g of ruthenium chloride, 4.5g of aluminum nitride and 4g of carbon black (rotation speed 500r / min) for 5h. Then, the ball-milled precursor mixture was pressed at 20MPa pressure for 1min, and the pressing was repeated 5 times to form a thin sheet. After that, the thin sheet was calcined at 1300℃ for 3h in an argon atmosphere to obtain a precursor Ir with a layered structure. x Ru y Al z C.

[0090] Then prepare the intercalation etching solution, slowly add 1g lithium fluoride into 50g 6mol / L hydrochloric acid solution under room temperature water bath conditions, and stir until the lithium salt is completely dissolved, then slowly add 1g precursor Ir x Ru y Al z C and heated in a constant temperature water bath at 40 °C for 10 h to x Ru y Al z C was intercalated and etched, and then the above product was centrifuged and washed with water for several times until the pH was 7 to obtain the etched Ir x Ru y C.

[0091] Stripping: Add 50 mL of deionized water to the above product and perform ultrasonic stripping for 2 h. Finally, centrifuge at a low speed of 2000 r / min to remove the blocky products and impurities that cannot be stripped. The upper liquid is retained and freeze-dried for later use to obtain the stripped layered metal carbide Ir x Ru y C nanosheets, and finally the dried layered metal carbide Ir x Ru y The C nanosheets were obtained by heating the temperature to 500°C at a heating rate of 5°C / min in an air atmosphere and calcining at high temperature for 3 hours.

[0092] Example 6

[0093] A method for preparing a two-dimensional anode catalyst, the specific steps are as follows:

[0094] First, 1g of chloroiridic acid, 2g of ruthenium chloride, 3g of aluminum powder and 4g of graphene were ball-milled (speed 500r / min) for 5h, and then the ball-milled precursor mixture was pressed at 20MPa pressure for 1min, and pressed into thin sheets 5 times, and then calcined at 1300℃ for 3h in argon atmosphere to obtain a layered precursor Ir x Ruy Al z C.

[0095] Then prepare the intercalation etching solution, slowly add 1g lithium fluoride into 50g 6mol / L hydrochloric acid solution under room temperature water bath conditions, and stir until the lithium salt is completely dissolved, then slowly add 1g precursor Ir x Ru y Al z C and heated in a constant temperature water bath at 40 °C for 10 h to x Ru y Al z C was intercalated and etched, and then the above product was centrifuged and washed with water for several times until the pH was 7 to obtain the etched Ir x Ru y C.

[0096] Stripping: Add 50 mL of deionized water to the above product and perform ultrasonic stripping for 2 h. Finally, centrifuge at a low speed of 2000 r / min to remove the blocky products and impurities that cannot be stripped. The upper liquid is retained and freeze-dried for later use to obtain the stripped layered metal carbide Ir x Ru y C nanosheets, and finally the dried layered metal carbide Ir x Ru y The C nanosheets were obtained by heating the temperature to 500°C at a heating rate of 5°C / min in an air atmosphere and calcining at high temperature for 3 hours.

[0097] Example 7

[0098] A method for preparing a two-dimensional anode catalyst, the specific steps are as follows:

[0099] First, 1g of chloroiridic acid was ball-milled with 2g of ferric chloride, 3g of aluminum powder and 4g of carbon black (rotation speed 500r / min) for 5h. Then, the ball-milled precursor mixture was pressed at 20MPa pressure for 1min, and the pressing was repeated 5 times to form a thin sheet. After that, the thin sheet was calcined at 1300℃ for 3h in an argon atmosphere to obtain a precursor Ir with a layered structure. x Fe y Al z C.

[0100] Then prepare the intercalation etching solution, slowly add 1g lithium fluoride into 50g 6mol / L hydrochloric acid solution under room temperature water bath conditions, and stir until the lithium salt is completely dissolved, then slowly add 1g precursor Ir x Fe y Al z C and heated in a constant temperature water bath at 40 °C for 10 h to x Fe y Alz C was intercalated and etched, and then the above product was centrifuged and washed with water for several times until the pH was 7 to obtain the etched Ir x Fe y C.

[0101] Stripping: Add 50 mL of deionized water to the above product and perform ultrasonic stripping for 2 h. Finally, centrifuge at a low speed of 2000 r / min to remove the blocky products and impurities that cannot be stripped. The upper liquid is retained and freeze-dried for later use to obtain the stripped layered metal carbide Ir x Fe y C nanosheets, and finally the dried layered metal carbide Ir x Fe y The C nanosheets were obtained by heating the temperature to 500°C at a heating rate of 5°C / min in an air atmosphere and calcining at high temperature for 3 hours.

[0102] Example 8

[0103] A method for preparing a two-dimensional anode catalyst, the specific steps are as follows:

[0104] First, 1g of chloroiridic acid was ball-milled with 2g of copper chloride, 3g of aluminum powder and 4g of carbon black (rotation speed 500r / min) for 5h. Then, the ball-milled precursor mixture was pressed at 20MPa pressure for 1min, and the pressing was repeated 5 times to form a thin sheet. After that, the thin sheet was calcined at 1300℃ for 3h in an argon atmosphere to obtain a precursor Ir with a layered structure. x Cu y Al z C.

[0105] Then prepare the intercalation etching solution, slowly add 1g lithium fluoride into 50g 6mol / L hydrochloric acid solution under room temperature water bath conditions, and stir until the lithium salt is completely dissolved, then slowly add 1g precursor Ir x Cu y Al z C and heated in a constant temperature water bath at 40 °C for 10 h to x Cu y Al z C was intercalated and etched, and then the above product was centrifuged and washed with water for several times until the pH was 7 to obtain the etched Ir x Cu y C.

[0106] Stripping: Add 50 mL of deionized water to the above product and perform ultrasonic stripping for 2 h. Finally, centrifuge at a low speed of 2000 r / min to remove the blocky products and impurities that cannot be stripped. The upper liquid is retained and freeze-dried for later use to obtain the stripped layered metal carbide Ir x Cu yC nanosheets, and finally the dried layered metal carbide Ir x Cu y The C nanosheets were obtained by heating the temperature to 500°C at a heating rate of 5°C / min in an air atmosphere and calcining at high temperature for 3 hours.

[0107] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing a two-dimensional anode catalyst, characterized in that: include: The iridium source is mixed with the active metal A source, the main group metal B source and the carbon source and pressed into a sheet, and then pyrolyzed and calcined under oxygen-free conditions to obtain a precursor Ir with a layered structure. x A y B z C; wherein the active metal A is ruthenium, iron, cobalt, nickel, manganese or copper, and the main group metal B is aluminum or silicon; The precursor Ir is etched x A y B z The main group metal B in C is removed, and layered metal carbide Ir is obtained through intercalation and stripping. x A y C; In an oxygen-containing atmosphere, the layered metal carbide Ir x A y C was oxidized and calcined to oxidize the carbide into oxide to obtain a two-dimensional layered metal alloy oxide catalyst Ir x A y O, that is, a two-dimensional anode catalyst.

2. The method for preparing a two-dimensional anode catalyst according to claim 1, characterized in that: The atomic ratio of the iridium atoms in the iridium source to the active metal A atoms in the active metal A source is 1:0.1-5; Or, the atomic ratio of the iridium atoms in the iridium source to the main group metal B atoms in the main group metal B source is 3:1-2; Alternatively, the mass ratio of the iridium source to the carbon source is 1:0.5-5.

3. The method for preparing a two-dimensional anode catalyst according to claim 1, characterized in that: The iridium source is selected from one or more of chloroiridic acid, iridium acetylacetonate, iridium chloride, potassium chloroiridate, sodium chloroiridate, and iridium acetate; Or, the active metal A source is a metal powder containing active metal A or one or more of nitrate, halide, sulfate, acetate, etc. of active metal A; Or, the main group metal B source is a metal powder containing the main group metal B or at least one of a carbide and a nitride of the main group metal B; Alternatively, the carbon source is selected from at least one of carbon black, porous carbon, mesoporous carbon, carbon nanotubes, nitrogen-doped carbon, boron-doped carbon, sulfur-doped carbon and / or phosphorus-doped carbon, carbon nanofibers, graphene and aerogel.

4. The method for preparing a two-dimensional anode catalyst according to claim 1, characterized in that: The temperature of pyrolysis calcination is 900-1500°C, and the time of pyrolysis calcination is 2-10h.

5. The method for preparing a two-dimensional anode catalyst according to claim 1, characterized in that: The etching method uses a mixture of lithium fluoride and hydrochloric acid solution as an etching solution; Preferably, the concentration of the hydrochloric acid solution is 1-6 mol / L, and the mass ratio of lithium fluoride to the hydrochloric acid solution is 1:10-50; Preferably, the precursor Ir x A y B z The mass ratio of C to etching solution is 1:10-100.

6. The method for preparing a two-dimensional anode catalyst according to claim 1, characterized in that: The precursor Ir is etched x A y B z The temperature for removing the main group metal B in C is 35-60°C, and the etching time is 10-24h.

7. The method for preparing a two-dimensional anode catalyst according to claim 1, characterized in that: After intercalation, the intercalation product is washed and then subjected to ultrasonic stripping; Preferably, during the ultrasonic stripping process, the solvent and the precursor Ir x A y B z The mass ratio of C is 10-100:1; Preferably, the ultrasonic stripping time is 0.5-3h.

8. The method for preparing a two-dimensional anode catalyst according to claim 1, characterized in that: In the oxidation calcination, the calcination temperature is 300-650°C and the calcination time is 1-3h.

9. A two-dimensional anode catalyst prepared by the method according to any one of claims 1 to 8.

10. Use of the two-dimensional anode catalyst according to claim 9 in producing hydrogen by electrolysis of water.

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